Section 3 - Motion stability and Linear equations

Question 1

In the case of path keeping, the most obvious external disturbing force would be a __________ or a _______________.

Answer 1

wave / gust of wind

Question 1

Achieving _____________ stability is the designer’s usual goal for most ships when steered by hand.

Answer 1

straight line

Question 1

In the ____________ plane in the open sea with stern propulsion, a self-propelled ship cannot possess either positional or directional stability with controls fixed.

Answer 1

horizontal

Question 1

A surface ship sailing a calm sea possesses positional motion stability in the ____________ plane with controls fixed.

Answer 1

vertical

Question 1

The only kind of motion stability possible in the horizontal plane is with controls fixed is ______________ stability, which is desirable, but not mandatory.

Answer 1

straight line

Question 2

The force required to accelerate a body in a fluid is always larger than the product of the actual mass of the body times its acceleration. This fact has given rise to the concept of ____________ or ____________.

Answer 2

entrained mass / added mass

Question 2

The added force due to entrained/added mass should be really interpreted as the hydrodynamic force arising because of the _____________________.

Answer 2

acceleration of the body

Question 3

The lateral force from the __________creates a moment to turn the ship. This turning action causes the ship to develop an angle of attack with respect with its motion through the water. The lateral forces then generated by the well designed ship, create a moment, that ______________________ the rudder moment.

Answer 3

deflected rudder / greatly augments